The technology relates to an automatic transmission to be mounted on a vehicle or the like, and in particular to an automatic transmission that includes a reduced-speed rotation output portion, a planetary gear set, first and second clutches, and first and second brakes to enable multi-stage speed change.
In recent years, it has been desired that automatic transmissions to be mounted on vehicles or the like should provide a multiplicity of speeds in view of the request to improve the fuel efficiency. Among such automatic transmissions, there is proposed an automatic transmission that includes a speed-reduction planetary gear that may output reduced-speed rotation obtained by reducing the speed of input rotation input to an input shaft and a so-called two-storied planetary gear set in which a plurality of planetary gears are combined with each other in the radial direction to provide six forward speeds and a reverse speed (see International Patent Application Publication No. 2013/159987).